Cindy Strnad on tue 16 may 00
Rhonda,
I don't know a lot about low-fired glazes, but if your glazes are running
off your pots, I think you need to increase your fluxes. Others far more
knowledgeable than I will undoubtedly jump in on this one.
I can help you more on the glaze blob problem, though. I use an angle
grinder (about $50 at a discount dept. store--mine's Black & Decker) with a
masonry wheel. Wear leather gloves and a dust mask, and tie back your hair.
It also works great for grinding blobs off your kiln shelves.
Cindy Strnad
earthenv@gwtc.net
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
friedlover on tue 16 may 00
I have been having fun playing with low fire glaze recipes, and they =
have beautiful runniness, but I want to reduce this somewhat.
I have read about 20 books in the last week and I'm still not clear.
Could someone tell me what I could add to decrease this?
Also interested in how others remove blobs from bottoms. Is there an =
easy way?
I have played with multiple dremmel attachments and I'm just not that =
patient!
Thanks.
Rhonda Fried
Paul Lewing on tue 16 may 00
friedlover wrote:
>
> I have been having fun playing with low fire glaze recipes, and they have beautiful runniness, but I want to reduce this somewhat.
> I have read about 20 books in the last week and I'm still not clear.
> Could someone tell me what I could add to decrease this?
Rhonda,
What you need to do is lower the ratio of silica to alumina in the
recipe, or increase the amount of refractory stuff (basically both the
Al and the Si) at the expense of the stuff that melts easily (the
fluxes).
The easiest and probably the best way to accomplish both these things is
to add clay, usually kaolin in a clear or light colored glaze. This
adds both Al and Si, in a proportion of about 2 Si to 1 Al, a ratio that
is well below that of any runny glaze. Just to give you a reference
point, most usable glazes have a ratio of between 5 and 12. A glaze
with a higher ratio, say, 16:1 or more, likely will be runny. Crystal
glazes, which always run, might have a ratio as high as 75 or 100 to 1.
A "lichen" glaze, on the other hand, might have a ratio of around 3, and
be quite dry, unless there is a lot of some other glass-former, like
boron.
To lower the ratio of Si:Al more dramatically, you could add alumina
hydrate, which adds Al, but no Si. This could also work.
Calculation software could be a real benefit here, as it's pretty easy
to spot a glaze that will be runny, and with a little practice, pretty
easy to determine where you need to take the Si:Al ratio. However, the
whole Seger formula method that calculation programs are based on
explains high-fire and mid-range glazes better than it does low-fire,
mostly due to the odd action of boron.
But, in two words: add clay.
Happy testing,
Paul Lewing, Seattle
Gregory D Lamont on wed 17 may 00
At 10:13 PM 5/16/00 -0600, you wrote:
>Rhonda,
>
>I don't know a lot about low-fired glazes, but if your glazes are running
>off your pots, I think you need to increase your fluxes. Others far more
>knowledgeable than I will undoubtedly jump in on this one.
>
>I can help you more on the glaze blob problem, though. I use an angle
>grinder (about $50 at a discount dept. store--mine's Black & Decker) with a
>masonry wheel. Wear leather gloves and a dust mask, and tie back your hair.
>It also works great for grinding blobs off your kiln shelves.
>
>Cindy Strnad
>earthenv@gwtc.net
>Earthen Vessels Pottery
>RR 1, Box 51
>Custer, SD 57730
>
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Cindy and Rhonda,
I think Cindy meant to say decrease the fluxes and increase alumina. If I
recall correctly, increasing the fluxes would lower the melting point,
further exacerbating the running problem. Decreasing the fluxes and/or
increasing the alumina would help to "stick" the glaze to the pot. I'm
sure Ron Roy, Paul Lewing, and the other glaze gurus will respond in
greater detail.
Greg
E-mail address:
gdlamont@isunet.net
Pottery Web Page:
http://www.ourwebpage.net/greglamont/
Mailing address and Phone:
Greg Lamont
3011 Northwood Drive
Ames, IA 50010-4750
(515) 233-3442
Lois Ruben Aronow on wed 17 may 00
> I can help you more on the glaze blob problem, though. I use an angle
> grinder (about $50 at a discount dept. store--mine's Black & Decker) with a
> masonry wheel. Wear leather gloves and a dust mask, and tie back your hair.
> It also works great for grinding blobs off your kiln shelves.
>
Don't forget to wear goggles when you are grinding and chipping. Those glaze blobs
have a way of heading right into the eyes.
rg42@BELLSOUTH.NET on wed 17 may 00
I use a broken silicon carbide kiln shelf attached to my kick wheel head
using a bit of clay, to grind bottoms. Makes them nice and flat. If dust
is an issue, you can wet grind using a little water. I had to use this
method in the classroom for safety reasons.
Richard Gilbert
Cherryville, North Carolina
Cat81257@AOL.COM on wed 17 may 00
Creative industries has a great sander out .. its expensive but dang
cuts like butter ... think axner or one of those places carries it if
not email me and I'll get the address for you cat81257@aol.com
ARTISTINSC@AOL.COM on tue 13 jun 00
Dear Cindy,
There are ever changing issues involved here.The resolution can be relative
to the size of the images you will ultimately use.There are little plastic
cameras now with 400x600 something that are ok for use to just give a decent
impression of the subjects over the internet and are used on Ebay all the
time.They would be good also to have for a child to practice their skills as
you never develop film and a computer is needed usually with a USB port
although some have a parallel port ,too.They store images in one or more
modes of resolution and i suggest using the high resolution if you can and
download to disc on the computer frequently.These are great for email and to
share online and for kids to pprint out.
The "BEST" cameras will be much like your slr cameras with interchangeable
lenses and filters and well over 3 million pixels resolution for larger size
images.They are available now but are over $5000 AND COMING DOWN IN
PRICE.They will download to a computer or dedicated printer without computer
and come with a version of photoshop to make all kinds of adjustments as a
professional photographer.Minolta makes some good ones as do other top
traditional slr and medium format manufacturers.
I also like the video digital cameras that take a still and take them onto
digital or 8 or hi8 tapes.These cameras also feed into the computer with a
variety of feeds from analog, parallel, usb and ieee and s.The speed of the
download and compatibility to the computer is the factor to look for.There
are a number of editing systems from companies for these like Pinnacle, for
one.The new computers coming out for fall will have the newest Microsoft
edition and many more media features than we now enjoy so if you are in the
market for high end stuff you might consider waiting until thatt has been
out and evaluated and the price has adjusted some.I suspect the technology is
about to take a big leap foreward here.The low end camera might be ok with
your slr 35mm until then.There are many ways to add slides and negative
scans out and improving, as we write. and these new computers and software
will pull all that together.There are a lot of online sites to buy stuff but
check them all out .I found Ebay not to be the best ,especially private party
sales of camera equipment, as the individuals can change id quickly and many
use library or kinko 's to go online and evaporate by the time your check
cllears and you are sent the equipment.There also is evidence they can bid
the stuff up themselves now.
Happy hunting.
Margaret
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